stuart8ol

Sorry - fixed now. Thanks for pointing that out.

Thanks - will definitely take a look.

They are aiming to be the propulsion system supplier for future aircraft but crucially the are also targeting developing systems for a family of aircraft starting small and are working towards aircraft upwards of 200 seats. Our premise is to not look past 50 seats. If we were to design a 200 seat aircraft its CASM would not be much cheaper than the 50 seat if we aim to do a single aircraft type from the start, then we can aim for much higher volumes than aircraft programs traditionally achieve and ultimately bring our unit costs right down and undercut anyone else working on a family of aircraft.

We were so close to buying an old Nomad for our tech demo! But we thought if we took it to an airshow, it would only get a small sub-set of attendees excited, compared to a Bonanza, which people seem to love. We would really love to do it all in Australia and think Australia is a great place to do the initial development work, flight testing our tech demo and retrofitting the first set of our B1900D-HE product. But we would, reluctantly, agree with you that the SA-1 design, testing and manufacturing would be at best global but most likely heavily centered in the USA. Its our plan to grow the team in the states, starting soon, and slowly shift the center of gravity as the projects move through maturity.

The air needed for the chemical reaction is pretty small, but we will also be drawing in some air for cooling and that will be around the same order of air that is used by a turbine engine. We will not have an APU per se, but we will have a small amount of battery to start the propulsion system and this can provide power to the aircraft systems for some time. We can also start up the fuel cells if need be to supply extra power, without turning the electric motor and propellers.

The lowest hanging fruit is the current 50-80 seat turboprop market. Next would be the regional jet market and lastly we want to capture a sizeable portion of the single -aisle market. The reason we want to compete with/capture traffic served by 737s and the like is that the market is enormous - we are estimating $1.7T over the next 20 years if we were to replace single-aisle with our 50-seat, SA-1. The reason that we believe we could compete is because we believe that we could bring the CASM of the 50-seater down to be on par with a 737, and combined with the emission reduction we think that this is compelling offer for airlines. Our aim is not to have to compete with 737s at airports that are slot constrained but to make use of the 100s of underutilised airports across America. By bringing down the CASM of a 50 seater, we believe that this would increase the passenger traffic too and from those airport and make the currently thin routes more profitable.

No that wouldn't have been us. Hope the feedback they received was "Australian aerospace company - great idea!" though.

My pleasure! Yeah working with the H3X team has been great. We are going to have them out at the airport before the end of the year, letting them run some tests on our set up. Will be fun.

Yeah even with today's batteries there is a business case for battery electric flight. Trainers, short hops across water and intracity + eVTOLs of course all make sense to tackle with battery. This is because the efficiency is good, the cost can be potentially very low and the infrastructure is manageable. But as a solution to decarbonising a large proportion of aviation - it doesn't work. We want to find a solution to serve the enormous number of passengers that fly up to 3000 km. If we can tackle that, we can cut more than 50% of aviation emissions.

One thing we have learned on this journey is how much low noise is to our customers and the wider community - we have yet to really put this under test and try and get a cost number against it i.e. how much more would you pay for a quieter engine? What we do have is an opportunity to be much quieter, but there is always a penalty to pay in terms of size. For example, unlike a battery aircraft, we still have to provide the fuel cells with air and we can do that with large quiet ducts or small noisy ones - but larger ones take up valuable real estate and ultimately add weight to the system. What I can say is we will design it to be quieter than current jet engines, but where we draw the line is tbd.

I think I would be hard pressed to say maintenance free but definitely significantly lower maintenance costs. Turbine blades are intrinsically expensive, made of titanium and operate at high temperatures under high loads. Electric motors have much simpler operation and when made at scale, can really benefit from a replace after 20,000 hours model, instead of a overhaul every 1800 hours, with 200hrs inspection intervals, which we see in some turboprop engines. Fuel cells and batteries are much the same, replace after a certain life, and with built in tolerance to failures. Unfortunately, with fuel cells, as opposed to batteries, we still have some balance of plant that will need maintained, compressors for example, however unlike a turbine engine, they don't operate at high temperatures and are a smaller part of the system, so we can design for much longer lifetimes that you can get away with in a turboprop. All this leads us to estimating 65% saving on engine maintenance. Battery electric companies are going after more like a 90% saving.

I think that is a fair statement. You also have to factor in the capital costs, the aircraft purchase price per seat typically increases with aircraft size so it comes down to the balance there, between that cost increasing and other costs decreasing. The scales can tip either way depending on the circumstances. For a 737, we have that capital costs contribute about 40% of the CASM, whereas Crew is 4% and Maintenance is 16%. In conventional aircraft, the efficiency of larger engines really vs smaller ones really push towards larger aircraft.

Thank you, I can confirm it is the coolest job I have had so far, and I have done quite a few cool things. I can also tell you, as someone who studied physics, I have only really spent about 10% of my time in the last year doing any physics! So much other stuff to get through...